Teaching aid of a non-orientable surface



FIG. 1 is a front elevation view of a teaching aid of a non-orientable surface showing my new design;

FIG. 2 is a bottom-front plan view of FIG. 1;

FIG. 3 is a top-front plan view of FIG. 1;

FIG. 4 is a rear elevation view of FIG. 1;

FIG. 5 is a top-rear view of FIG. 4;

FIG. 6 is a bottom-rear view of FIG. 4.

FIG. 7 is a cross-section view thereof taken in the direction of line 7-7 of FIG. 1;

FIG. 8 is a cross-section view thereof taken in the direction of line 8-8 of FIG. 1;

FIG. 9 is a cross-section view thereof taken in the direction of line 9-9 of FIG. 1; and,

FIG. 10 is a cross-section view thereof in the direction of line 10-10 of FIG. 1. 

CLAIM The ornamental design of a teaching aid of a non-orientable surface, as shown and described. 